CAMBODIA: Once ‘Extinct’ Crocodile Claws Its Way Back to Survival

PHNOM PENH, Nov 20 2009 (IPS) - Siamese crocodiles once ranged far and wide across South-east Asia, from Indonesia to Vietnam, Laos to Thailand. But habitat loss and poaching virtually wiped out the three-metre long animals. Twenty years ago they were classified as effectively extinct in the wild.
That seemingly terminal news was partially offset in 2000 when researchers discovered several dozen of them living in the wild in south-west Cambodia. Experts now believe there are 250 Siamese crocodiles living in the wild in the region, and almost all of those are in Cambodia.

Today the Siamese crocodile is listed as critically endangered on the Red List of the International Union for Conservation of Nature. Its precarious position explains why DNA test results announced this month from a Cambodian wildlife centre were greeted with such relief.

The tests, which were carried out by Thailand’s Kasetsart University, found that 35 of 69 crocodiles at the Phnom Tamao Wildlife Rescue Centre outside Phnom Penh are purebred Siamese crocodiles, not hybrid animals as experts had feared.

It means the species has a much better chance to claw its way back from the brink, says Adam Starr, who heads the crocodile programme at Fauna & Flora International, a conservation organisation.

Describing the test results as “really encouraging,” Starr says a proposed breeding and release programme now stands a far greater chance of success.

“Siamese crocodiles used to exist throughout South-east Asia … but now they are reduced from about 99 percent of their original population range area,” Starr says. “We can say Cambodia hosts between 95 and 99 percent of the remaining wild crocodiles.”

Siamese crocodiles were pushed to the brink of extinction—and some thought over it—by two factors: habitat loss and poaching. The reason they were hunted almost to extinction in the wild is that their skin is much softer than that of other crocodiles.

Nhek Ratanapech, the director of the Phnom Tamao Wildlife Rescue Centre, which is home to the 35 purebred Siamese crocodiles, describes the population as “on the verge of extinction”.

“This could provide a critical lifeline for the long-term preservation of this critically endangered species,” he says of the DNA results.

Nhek Ratanapech, who also heads the country’s crocodile conservation programme, says six of the 35 purebred Siamese crocodiles are mature adults which are unrelated to each other—vital for ensuring genetic diversity. The 29 remaining animals are hatchlings, which will be released into the wild once they are two years old.

The six adults will form the core of a breeding programme, and their offspring will be released into the wild once they reach two.

The aim of the proposed breeding programme is to increase the number of mature animals in the wild to 500. If and when they can achieve that, he says, the animal will be taken off the IUCN’s critically endangered list.

Nhek Ratanapech says that prior to the DNA tests, the centre had no way of knowing for certain which of the dozens of crocodiles in its keeping were purebred and which were hybrid.

Starr says that meant researchers could not risk releasing the animals into the wild because hybrids would pollute the gene pool. He explains that hybrids are the product of crocodile farms crossbreeding Siamese crocodiles with more aggressive species such as saltwater crocodiles. The result is a larger, faster-growing animal that still gives soft leather.

“The fact that we actually have 29 young animals is like jumpstarting the programme,” Starr says. “Initially, I didn’t think any of the young crocodiles would be [pure-bred] Siamese. But we can now begin planning for introductions we make in the future.”

“[We will] be able to reintroduce animals to areas where Siamese crocodiles once existed but have been eradicated due to poaching,” he says. “So it’s a very exciting phase we’re about to embark upon.”

Given that Siamese crocodiles take 15 years to reach maturity, this is a long-term project. And although poaching has declined since the 1980s and 1990s, the animals will still face challenges in the wild. Starr lists habitat encroachment and Cambodia’s plan to build numerous hydroelectric dams on its rivers as key issues.

Despite that, the experts remain optimistic. Starr says that over the next 12 months the programme will locate five areas with habitats suitable for the release of wild hatchlings. Varying the release zones cuts the risk of disease wiping out the entire population in the wild.

They will also work with the local communities in those areas to explain the programme.

Success for the Siamese crocodiles means more than revitalizing the country’s biodiversity. The animals are prominent in Cambodia’s culture and religion, and are even portrayed in carvings on the walls of Angkor Wat temple in the country’s west.

Starr says that cultural value adds to the importance of the breeding programme. And although he is optimistic that this crocodile—among the rarest in the world—can make a comeback, he is still cautions against complacency.

“This is the first step of about 1,000 steps we have to take right now. It’s encouraging, but we should not be jumping for joy too quickly,” Starr says.